1. Field of the Invention
The present invention relates to a hood of a motor vehicle, and more particularly, the present invention relates to a hood raising mechanism of a motor vehicle, which can raise a hood when the vehicle hits a pedestrian so that impact applied to the head of the pedestrian is mitigated.
2. Description of the Related Art
Generally, in an engine room which is defined at a front part of a motor vehicle, there are disposed an engine, a cooling system, and a variety of devices which are needed for driving the vehicle. As shown in FIG. 1, a hood closes the engine room such that these arrangements are not exposed to the outside.
Referring to FIG. 2, there is illustrated an assembling structure of a hood to a vehicle body. The hood 100 has a hood outer panel 103 and a hood inner panel 104 which are overlapped with each other. The hood 100 is assembled to the vehicle body 110 in a manner such that it can be pivoted about a hinge section adjacent to a rear end of an engine room.
The hinge section for pivotably assembling the hood 100 to the body 110 includes a hood-side bracket 105 which is fastened to a lower surface of the hood 100 and a body-side bracket 106 which is fastened to an upper surface of the body 110. Due to the fact that the hood-side bracket 105 and the body-side bracket 106 are hingedly connected with each other by a hinge pin 101, the hood 100 is pivotably fastened with respect to the body 110.
Normally, the hood 100 is held at a closed position where it closes the engine room. When it is necessary to conduct maintenance and repair works for arrangements disposed in the engine room, by upward pivoting movement of the hinge section about the hinge pin 101, the engine room is opened. On the other hand, while not shown in the drawings, a hood latch mechanism is installed on a front end of the hood 100. The hood latch mechanism functions to lock the hood 100 so that the hood 100 is not spontaneously opened while being at the closed position.
On the other hand, the drawing reference numeral 102 represents a shotgun which projects upward out of the upper surface of the vehicle body 110. The shotgun 102 functions to prevent, to some extent, the body 110 from being crushed when the vehicle hits an obstacle, by partially absorbing a load applied to the body 110. Also, the shotgun 102 functions to guide rainwater to the outside of the body 110 when it rains. Due to this, the shotgun 102 is also called a rain rail.
When the vehicle hits a pedestrian, the pedestrian is thrown toward the engine room, and by this, the head of the pedestrian is bumped against the hood 100 which covers the engine room. In the case of an adult, the head is mainly bumped against a region A of FIG. 1, and in the case of a child, the head is mainly bumped against a region B of FIG. 1. If the head of the pedestrian is bumped against the hood 100, the hood 100 is deformed downward, and the head of the pedestrian is secondarily bumped against arrangements such as en engine, which are positioned below the hood 100, by the medium of the hood 100. In the case that the head of the pedestrian is simply bumped against the hood 100, an injury rate of the pedestrian""s head is decreased, when compared to the case that the head of the pedestrian is bumped by the medium of the hood 100 against the arrangements which are positioned below the hood 100. Consequently, when the vehicle hits the pedestrian, even though the head of the pedestrian is bumped against the hood 100, it is necessary to prevent the head of the pedestrian from being further bumped, through the hood 100, against the arrangements positioned below the hood 100.
To this end, a predetermined separation should be maintained between the hood 100 and the arrangements which are disposed in the engine room. For example, it is prescribed in the U.S. law for protection of an pedestrian that a distance of no less than 50 mm in the case of a child (corresponding to the region B of FIG. 1) or 70 mm in the case of an adult (corresponding to the region A of FIG. 1) is secured between the hood and the arrangements which are positioned below the hood.
Since the conventional hood constructed as mentioned above only has a separation of about 40 mm between the vehicle body and the hinge pin, in order to increase a separation between the hood and the arrangements in the engine room, it is necessary to increase a height of the hood or modify structures of a fender and a cowl of the vehicle body, which delimit the engine room. In this case, because the hood comes off the fender, forward and downward visibility of a driver is deteriorated and aesthetic appeal of the vehicle body is reduced.
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to maintain a sufficient separation between a hood and arrangements in an engine room so that an injury rate of a pedestrian""s head is minimized when a vehicle hits the pedestrian, while not deteriorating forward and downward visibility of a driver and reducing aesthetic appeal of a vehicle body.
In order to achieve the above object, according to the present invention, there is provided a hood raising mechanism of a motor vehicle, comprising: a sensor installed at a front part of a vehicle body for sensing hitting of the motor vehicle against an obstacle; a plunger member received in a receiving portion which is formed in a fender of the vehicle body, in a manner such that the plunger member can be moved upward to raise a rear end of the hood, the plunger member being defined at a lengthwise middle portion thereof with an engaging groove; a compression spring for elastically biasing upward the plunger member; a locking pin capable of being moved in such a way as to be engaged into or disengaged from the engaging groove defined in the plunger member; and an actuator for moving the locking pin in response to a signal inputted from the sensor, so that the locking pin is disengaged from the engaging groove to allow the plunger member to be moved upward.
Preferably, the locking pin may be formed on a circumferential outer surface thereof with a first gear; and the actuator may have a second gear which is meshed with the first gear of the locking pin and a motor for driving the second gear.